98 vortec 350 swap

[72shortbed12]

I picked up a 98 vortec 350 with 70k miles for $400. It sat for a couple years so the guy tore it down to put new gaskets and seals in. He's getting divorced and had to sell his unfinished projects. It came with everything for the motor plus radiator, computer and wiring harness. Thinking about putting it in my 72 k10 but don't have a bunch of money to throw at it. I've searched on the forum and elsewhere but can't find much info on running my sm465/205 trans, t-case behind it. What am I looking at needing to find for parts? I know the fuel tank, pump and lines are a must. Do I need a different bell housing? Do I have to switch to a hydraulic clutch? Motor mounts? Speedometer? Can I expect a mileage increase over a carb'd motor? If it is expensive I'll just sell it to a friend who wants one for his 93 blazer. Its not a big deal to me. thanks

[mrein3]

Just get an intake for it ($100 used, $200 new) run a carb, everything else is the same as a 1972 350. Provided it has a mechanical fuel pump. If not you'll have to run an electric.

[Tx Firefighter]

If you go carb, you're gonna be leaving about 5+ mpg on the table versus the EFI.

[QKENUF4U]

loved my 96 z71 vortec 350 (in my 96 z71 lol) that motor in a 67-72 would have been AWESOME !!
all i can tell ya is figure it out and do it cause i dont see you being disappointed unless the motor was trashed before he pulled it....
good luck

[knuckledragger]

I put one of these in my 63 belair wagon a couple of years ago.You will need an intake[carberated] an electric fuel pump,flywheel[one piece rear seal].If you are running the short syle water pump,you will have to change the front plastic timing cover.This is a great upgrade for your truck.My wagon hauled a$$ with a stock engine with a qjet.It would get up to 20 on the hiway with a 700 behind it.I say do it either carbed or efi.

[SoCal71K20]

Can't go wrong with that motor, if it's in pretty good shape. Got that year Suburban with that vortec motor and it just won't quit. Sounds like you got it for a decent price too. Yeah, I'd run it carbed or fuel injected. Either way, you'll need electric fuel pump to match which way you go with it. Me, I'd run a Carter/Edelbrock AFB and call it good. Good luck.

[veinbar]

I put a '98 Vortec 350 Tahoe motor in my '76 SWB Chevy Sport Van. I converted mine to carburetor (Q-Jet). I never completely resolved my fuel delivery issue, but is was noticeably more powerful than a crate motor, and the MPGs were very impressive. In that van I consistantly got around 17 + mpg on the hwy. I even broke 18 a few times. My foot was the main contributor to bad fuel economy.

(906 headed vortec stock, performer intake, QJet, 700r4 A/T, 3.73 Posi rear, Dual 2" Sidepipe exhaust.) This was a recipe for great hwy cruising with plenty of burnout power.

[72shortbed12]

Running the carb setup doesn't sound like a bad idea on it either. I was planning on doing vortec heads on the motor i have now and running a carb intake.
Would I benefit much from the vortec carb' d compared to an older motor with vortec heads? The motor I have only has 15,000 miles on it. Runs great. The fuel injection would be awesome but from what I've read I'd be better off to put in a nv4500 with it If I want to run a manual trans and I don't have the budget for it right now.

[mrein3]

Originally Posted by Tx Firefighter

If you go carb, you're gonna be leaving about 5+ mpg on the table versus the EFI.

Tx Firefighter, I have to respectfully disagree with you on this one. Maybe a poorly tuned carb will leave that many miles per gallon on the table. And yes day in and day out the self adjusting air/fuel mixture from EFI verses carb will always win but you're talking 15 mpg verses 10 mpg. If you've proven this please let me know. I have a 99 vortec 350 on the stand in the garage and would love to squeeze 15 mpg out of my 10 mpg truck.

[72shortbed12]

15 mpg would be great. Maybe I'll try the carb intake. I can swap the efi in later.
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[72shortbed12]

Been looking into the swap more and this is what I've come up with. I can bolt my original bellhousing with the sm465/205 and use my manual clutch. I can keep the mechanical oil pressure gauge and speedometer cable. Have the computer flashed to get rid of the emissions, oil pressure gauge and vss. Install the motor and wiring harness. Wire in my ignition switch to the system and install a fuel tank with in tank pump to run 55-60 psi. Does this sound right?
Anything major I'm missing?

Thanks for all the replies.

[Rob H.]

I've got a .040 over 350 in my 96 Suburban, I had just rebuilt before we got flooded, I managed to save the engine. I've been eyeing it to swap into my 72 in place of the original 307. I've kinda been holding off as I also have a 98 Tahoe that's pushing 200,000 and nowhere near the power of the suburban engine, since it's become my tow rig alot of the time it might catch the 96 vortec instead. But then I think how fun it'd be having it in my 72!

[project67-stepside]

u have the perfect setup all ready to go leave the serpentine and rewire but u will need and electric fuel pump because the bock doesnt have the knockout

[HEISEL]

I have a 72 k/10 swb and im doing the same swap. Im in the act of gitting all the parts. I do a lot of offroading so im going to go efi. The setup I'm putting on it will be a tbi kit(keeping it simple) from howellefi.com. They will sell you a tbi kit for $1300. or you can put your own setup in and they will sell you a wiring harness. This kit gives you a GM brain box and tb. Check it out. and if you have the money you can get a edelbrock mpfi with the kit and it comes out to $1800 for the hole kit i think. I have a friend that got this kit for his 78 jeep and its the best mod he ever did. think about it, no more cold starts, any hill any time. worth it! all you carb guys can save your hate mail. You have to get the vortec carb intake for your carb. you can always do this down the road as this kit bolts to the carb intake.

[Ackattack]

The one thing I see, it I believe you need a new flywheel for the 1 piece rear main seal engine. Everything else "should" bolt up. You may need a vss box for your speedo output. I'm not sure how the ECM uses the vss, so that may require some more research. It may only use it to control the auto tranny that was behind the original engine....but it may use it for other things.

One suggestion that I have, that I ran into with my 97 tahoe, is to remove the quick disconnect heater hose outlet from the intake and put on a hose nipple. The QD on mine broke one day. Its not a very durable fitting.

Oh, and I'd keep the EFI, no doubt....but I'm not scared of EFI

[72shortbed12]

I hope all I need is a flywheel. This is turning into a budget project and the wife keeps cutting the budget so I better get on it. I'll have to look into the vss functions. I already planned on removing the quick disconnect intake fitting. Just broke one last month on a 4.3 vortec. Impossible to get out with red locktight on the threads. Luckily I had another intake so I didn't have to buy a tap.